Technical Field
The present invention relates to a fixing device and an image forming apparatus including the same.
Background Art
In a fixing device employed in an image forming apparatus, a heat roller fixing system or belt fixing system is one way to fix a toner image to a recording medium such as a sheet of paper or the like.
In the heat roller fixing system, a fixing roller incorporating a heating device, such as an infrared heater, and a pressure roller that presses against the fixing roller form a nip portion, the recording medium carrying an unfixed toner image thereon is sandwiched by and conveyed through the nip portion, is heated and pressed, and the unfixed toner image is fixed onto the recording medium.
In the belt fixing system, an endless fixing belt is stretched around the heat roller that incorporates the infrared heater, and the fixing roller; a nip portion is formed by a pressure roller and the fixing belt; and the recording medium carrying an unfixed toner image is sandwiched and conveyed in the nip portion and is heated and pressed, to thereby fix the unfixed toner image thereon.